An arc furnace is used to produce liquid metal, generally steel. The liquid metal is produced from solid material to be melted, for example scrap metal or reduced iron, together with further additives. This is done by using one or more electrodes to introduce energy into the arc furnace in order to melt the material to be melted, generally in the form of an arc between an electrode and the material to be melted. In order to allow the melting process to be carried out as efficiently as possible, as much as possible of the energy produced by the arc should be introduced into the material to be melted. In this case, the material to be melted means solid material, liquid metal and/or slag, as well, to be melted.
However, the specified method of operation of present-day arc furnaces means that the arc burns freely during the melting process. This means that a large proportion of the thermal radiation which originates from the arc formed between an electrode and the material to be melted strikes a boundary of the arc furnace, in particular a cooled wall of the arc furnace. This increases the energy consumption of the furnace, on the one hand because only a small amount of the energy in the arc furnace is introduced into the material to be melted, while on the other hand the cooling power to cool the furnace walls may have to be increased.